Spring

ABSTRACT

A heavy-duty spring device with a series of axially arranged rigid outer rings and having resilient split inner rings sandwiched axially therebetween. The inner and outer rings have curved interacting surfaces whereby, upon the application of an axial force, the inner rings are compressed with the axial force being substantially absorbed.

United States Patent App]. No. Filed Patented Assignee Priority SPRING 12 Claims, 18 Drawing lFigs.

US. Cl

Int. Cl Fl6f1/38 [50] Field of Search 267/135, 152, I53, I62

[56] References Cited UNITED STATES PATENTS 1,816,325 7/l93l Held .i 267/]35 3,493,221 2/1970 Mozdzanowski 267/l53 Primary Examiner-James B. Marbert Attorneys-Edward F. Jurow and Clifford A. Dean ABSTRACT: A heavyduty spring device with a series of axially arranged rigid outer rings and having resilient split inner rings sandwiched axially therebetween. The inner and outer rings have curved interacting surfaces whereby, upon the application of an axial force, the inner rings are compressed with the axial force being substantially absorbed.

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MAXIM/LIAN RUSSOLD INVENTORS PATENTED SEP28 I97! 3.888.883

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PATENTEU SE'P28 197i 3 6 O8 883 sum a nr 8 SPRING BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention pertains generally to spring or shock absorbing devices which are adapted for relatively heavy-duty applications, such as for cushioning impacts between railway cars.

2. Description of the Prior Art The present invention relates to a spring which consists of rings sandwiched in the direction of the force attack and in which radially slit, resilient inner rings alternate with rigid outer rings, in which system the outer rings have slide surfaces interacting with the inner rings, with generatrices inclined toward the axis. Springs of this general type are known per se and offer the advantage that they can absorb relative great forces. In the known springs of this type, the inner rings and the outer rings contact each other with conical slide surfaces, whereby there is yielded a linear characteristic curve of the spring.

SUMMARY OF THE INVENTION Now the present invention aims to improve upon such prior constructions and consists substantially in that the slide surfaces of the inner rings and of the outer rings have curved or bent generatrices at the contact places. Through such a conformation or shape of the slide surfaces it is rendered possible to choose at will the characteristic curve of the spring. De pending on the curvature or bend of the generatrices of the slide surfaces there can be achieved a progressive or degressive spring characteristic. The slide surfaces of the outer rings, for example, can be constructed concave and the slide surfaces of the inner rings convex. In this case there results a progressive spring characteristic. If, for example, the slide surfaces of the outer rings are made convex and the slide surfaces of the inner rings are likewise made convex, there results a degressive spring characteristic. Still further variants are possible of the curvature or bend of the generatrices of the slide surfaces, whereby the spring characteristic can be correspondingly modified. In the case of a progressive spring characteristic there are achieved high terminal forces. A spring with degressive spring characteristics, again, presents a great work absorption. In the various cases of utilization of the spring, the one or the other design is advantageous and the invention makes possible the adaptation of the spring system to the requirements of the particular design application. The spring according to the invention is especially well suited, for example, for the cushioning of impacts between railway cars, and in this case a degressive spring characteristic, which can be achieved in a spring according to the invention, presents special advantages. On the one hand, it has a great work capacity, so that it renders possible the nullification of great amounts of energy in a collision, in which case the relatively slight terminal force reduces any endangering of the car and the detailing tendency of the same. The spring according to the invention is especially well suited for cushioning couplers of railway cars. In all cases it is possible, with maintenance of the desired type of spring characteristic to increase the spring travel by increase of the number of rings interacting with one another.

The sandwiched rings can be guided in various ways in an axial direction and be secured against radial displacement. Thus, for example, according to the invention the adjacent outer rings can overlap one another telescopically with guide surfaces. According to a preferred form of execution of the invention, however, the outer rings are constructed as bowlshaped elements which are guided on a central axis. The guidance on a central axis, which is made possible by the bowl-shaped construction of the outer rings, is more precise and is constructionally more favorable than the guidance at the outer periphery of the outer rings. Furthermore, the bowlshaped construction of the outer rings presents the advantage that in event of spring breakage, any broken resilient inner rings are maintained in their position, so that the functioning of the spring is only slightly impaired by spring breakage.

According to certain embodiments of the invention, the construction is expediently made in such a way that the resilient inner rings have in all places a cross section whose width is approximately equal to the height. Such a compact cross section of the resilient inner rings make possible a strong construction of the same and the achievement of high spring forces with a relatively short structural length of the spring.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. II is an axial sectional view of one embodiment of the present invention in an unstressed condition;

FIG. 2 is a plan view of one of the inner split ring members of FIG. 1;

FIG. 3 is an enlarged axial sectional view of one of the spring units of FIG. 1;

FIG. 4 is a force-travel diagram for the spring unit shown in FIG. 3;

FIG. 5 is an axial sectional view of another form of spring unit of the invention;

FIG. 6 is a force-travel diagram for the spring unit shown in FIG. 5;

FIG. 7 is an axial sectional view of yet another form of spring unit of the invention;

FIG. 8 is a force-travel diagram for the spring unit shown in FIG. 7;

FIG. 9 is an axial sectional view of still another form of spring unit of the invention;

FIG. 10 is a force-travel diagram for the spring unit shown in FIG. 9;

FIGS. Ill, l2, l3 and 14 are partial axial sectional views of four additional embodiments of the invention;

FIG. 15 is a traverse sectional view taken generally along the line 15l5 of FIG. l4;

FIG. 16 is a partial axial sectional view of a still further embodiment of the invention in an unstressed condition;

FIG. 17 is a partial axial sectional view of the embodiment of FIG. I6 when under axial compression; and

FIG. 1.8 is an axial sectional view of a still further embodiment of the invention whereby different force absorbing characteristics are provided upon the application of axial forces in opposite directions.

DESCRIPTION OF PREFERRED EMBODIMENTS As FIG. I shows, the spring consists of element pairs I, 2, stacked one upon another, which are guided on a central axial shaft 3. Each spring unit includes a rigid outer ring 1 in the form of a bowl-shaped element, within which there is home a radially slit, resilient inner ring 2, such as in represented in FIG. 2. The bowl-shaped elements l have slide surfaces or generatrices 4, which interact with the inner rings 2. When these resilient rings 2, upon the application of an axial force, are pressed into the bowl-shaped elements I, then, because of the conicity of the slide surfaces 4, their diameter has to diminish, whereby there is yielded the spring effect. The bowlshaped elements II have opposite hub surfaces 5, 6, which can come to rest on one another in the event of breakage of a spring ring 2. The lower rigid stop 7 is formed by a collar of the central axial shaft 3, while the movable stop 8 is annularly formed.

As is represented in FIG. 3 on a larger scale, the slide surfaces 4 have generatrices with a convex curvature. Thereby there is yielded a degressive spring characteristic and the spring offers a great working capacity. The force-travel diagram of the spring is represented in FIG. 4, in which the force I is represented on the ordinate and the travel S on the abscissa. The loading of the spring is shown by curve a and release of the spring is shown by curve b, with the area c representing the damping accomplished. Such a spring, accordingly, has a great work capacity.

In the arrangement according to FIG. 5, the slide surface 4a has a generatrix with concave curvature. There results thereby the progressive spring characteristic curve a represented in FIG. 6.

In the arrangement according to FIG. 7, the slide surface 4b has a bent or dipped generatrix, whose parts are rectilinear. Hereby there is yielded the spring characteristic curve a" represented in FIG. 8.

In the arrangement according to FIG. 9, the conical surface 4c has generatrices which at first run in a straight line and then go over in a bend into a convex line. The spring curve a hereby yielded is represented in FIG. 10.

In the arrangement according to FIG. 11, the outer rings 9 are formed of two-way bowl-shaped elements, which again are guided on a central axial shaft 3d, and have lower and upper slide surfaces 10 and 11, respectively, on opposite ends facing the adjoining elements, which surfaces interact with resilient inner rings 2d, 2d. On one end the outer rings 9 are provided with a skirt-shaped added piece 12, which surrounds the resilient inner rings 2d, 2d and protects them when the spring is unloaded.

In the embodiment represented in FIG. 12, there is provided in place of the two inner rings 2d, 2d, a single resilient inner ring 132, which has a cross section elongated in the axial direction of the force attack. Through this elongated cross section it is made possible to arrange only a single resilient inner ring 13c between each adjacent pair of outer rings 9e formed of two-way bowl-shaped elements, the desired spring path nevertheless remaining preserved.

The embodiment according to FIG. 13 differs from the embodiment according to FIG. 12 substantially in that the resilient inner rings 13f are subdivided into an inner annular part 13f and an outer annular part 13f. The outer rings 14, again formed of two-way bowl-shaped elements, are distinguished from the outer rings 9 according to FIG. 12 only in that the skirt-shaped added piece 12 is omitted. The two ring parts 13f and 13] lie with profiled annular surfaces 15 on one another and are secured against axial displacement by the profiling of these annular surfaces 15. The inner annular part 13]" undergoes a greater deformation in the compression of the spring than the outer annular part 13] and this annular part, therefore, is constructed of a material having a higher limit of elasticity.

In the arrangement according to FIGS. 14 and 15, the outer rings 16 again have oppositely facing slide surfaces 10g, 11g, which interact with an adjacent pair of resilient inner rings 17. The outer rings 16 in this embodiment are not constructed as bowl-shaped elements and are not guided on a central axial shaft. The guidance takes place in this embodiment on the outside by skirt-shaped additions 18, which telescopically overlap cylindrical surfaces 19 of the next adjacent outer rings 16 and slide on these. In this embodiment, the resilient inner ring 17 has a cross section which decreases progressively toward the gap 20 defined between its split ends.

The embodiment according to FIGS. 16 and 17 corresponds approximately to the embodiment according to FIG. l, in which, however, the resilient inner rings 21 have a different cross section. The rigid outer rings 22, which again are constructed as bowl-shaped elements and are guided on a central axial shaft 3h have an outer flange 23, which is made of such a height that the individual outer rings 22, when the spring is fully compressed (FIG. 17), lie against one another along their outer periphery, so that the flanges 23 provide an end limit of the spring travel. This outer peripheral engagement of the bowl-shaped elements 22 provides a better end stop than the engagement of the hubs at the-inner circumference of the bowl-shaped elements 22.

In FIG. 18 there is represented a further embodiment in which the spring system can be subjected to axial forces in opposite directions. The forces are applied through an end piece 25 connected to or integral with the central guide rod 3k, with a lug or fixed counterbearing 26 being provided at the opposite end. With a force application in the direction of the arrow A, the spring elements, formed of rigid outer rings 14k and resilient inner rings 13k, are pressed together between a shoulder 27 or the end piece 25 and the counterbearing 26. A fixed annular intermediate stop 28 is provided which has an inner diameter which is greater than the outside diameter of the outer rings 24k but smaller than the outside diameter of a flange 29 of the modified outer ring 14k". With a force application in the direction of the arrow A, therefore, this intermediate stop 28 is out of operation.

In the case of a force application in the direction of the arrow B, the force is transmitted over the guide rod 3k, a nut 30, and an annular plate 31 to the inner and outer spring elements. Since the flange 29 of the outer ring 14k" is supported against the stop 28, with a force application in the direction of arrow B only the two resilient inner rings 13k and 13k are deformed. This embodiment thus provides different spring travel and different force absorbing characteristics for axial forces applied in opposite directions.

While there have been shown and described several preferred embodiments of the present invention, it will be understood by those skilled in the art that still further modifications and rearrangements may be made without departing from the spirit and scope of the invention.

We claim:

1. A spring comprising, a series of rigid outer rings arranged along an application of force axis and each having a slide surface inclined generally toward said axis, and a series of inner resilient split rings sandwiched between said outer rings and having slide surfaces interacting with said slide surfaces of said outer rings, said inner rings being nondeforrnable in the direction of said application of force axis whereupon said inner rings are circumferentially compressed upon the application of a force along said axis, said slide surfaces of said outer rings being curved to provide a desired spring characteristic.

2. The spring set forth in claim 1 wherein the outer rings are constructed as bowl-shaped elements and are guided on a central axle shaft.

3. The spring set forth in claim I wherein the resilient inner rings have a uniform cross section whose width is approximately equal to its height.

4. The spring set forth in claim 1 wherein the outer rings are bowl-shaped at both ends whereby each outer ring interacts with the pair of resilient inner rings adjacent thereto.

5. The spring set forth in claim 4 wherein a pair of inner split rings are provided between each two adjacent outer rings, each split ring being disposed against a slide surface of the adjacent outer ring.

6. The spring set forth in claim 4 wherein an inner split ring having a cross section elongated in the axial direction is disposed between each two adjacent outer rings, whereby the split ring engages the slide surfaces of the two adjacent outer rings.

7. The spring set forth in claim 1 wherein the outer rings have skirt-shaped portions surrounding the resilient inner rings and overlapping the adjacent outer ring.

8. The spring set forth in claim 1 wherein the adjacent outer rings overlap one another telescopically with guide surfaces.

9. The spring set forth in claim 1 wherein the resilient inner rings are radially subdivided into two annular parts which lie snugly against one another.

10. The spring set forth in claim 9 wherein the inner annular part consists of a material of higher limit of elasticity than the outer annular part.

I 1. The spring set forth in claim 9 wherein the inner annular part and the outer annular part lie against one another with profiled annular surfaces whereby same are secured against axial displacement relatively to one another.

12. The spring set forth in claim 1 wherein the spring travel is limited by engagement of the outer rings against one another, the stop surfaces preferably lying at the outer edge of the outer rings. 

1. A spring comprising, a series of rigid outer rings arranged along an application of force axis and each having a slide surface inclined generally toward said axis, and a series of inner resilient split rings sandwiched between said outer rings and having slide surfaces interacting with said slide surfaces of said outer rings, said inner rings being nondeformable in the direction of said application of force axis whereupon said inner rings are circumferentially compressed upon the application of a force along said axis, said slide surfaces of said outer rings being curved to provide a desired spring characteristic.
 2. The spring set forth in claim 1 wherein the outer rings are constructed as bowl-shaped elements and are guided on a central axle shaft.
 3. The spring set forth in claim 1 wherein the resilient inner rings have a uniform cross section whose width is approximately equal to its height.
 4. The spring set forth in claim 1 wherein the outer rings are bowl-shaped at both ends whereby each outer ring interacts with the pair of resilient inner rings adjacent thereto.
 5. The spring set forth in claim 4 wherein a pair of inner split rings are provided between each two adjacent outer rings, each split ring being disposed against a slide surface of the adjacent outer ring.
 6. The spring set forth in claim 4 wherein an inner split ring having a cross section elongated in the axial direction is disposed between each two adjacent outer rings, whereby the split ring engages the slide surfaces of the two adjacent outer rings.
 7. The spring set forth in claim 1 wherein the outer rings have skirt-shaped portions surrounding the resilient inner rings and overlapping the adjacent outer ring.
 8. The spring set forth in claim 1 wherein the adjacent outer rings overlap one another telescopically with guide surfaces.
 9. The spring set forth in claim 1 wherein the resilient inner rings are radially subdivided into two annular parts which lie snugly against one another.
 10. The spring set forth in claim 9 wherein the inner annular part consists of a material of higher limit of elasticity than the outer annular part.
 11. The spring set forth in claim 9 wherein the inner annular part and the outer annular part lie against one another with profiled annular surfaces whereby same are secured against axial displacement relatively to one another.
 12. The spring set forth in claim 1 wherein the spring travel is limited by engagement of the outer rings against one another, the stop surfaces preferably lying at the outer edge of the outer rings. 